The invention relates to a conveyor for orienting and feeding small parts such as studs, pins, screws, and the like, having a platform elevator conveying mechanism that is arranged on one side of an inclined collecting surface and that feeds small parts to a conveying trough located at a higher elevation.
A conveyor of the specified type is known from DE 199 43 164 A1. In the prior art conveyor, the conveying trough is located in a fixed position immediately adjacent to the conveying platform of the platform elevator conveying mechanism and is inclined at such an angle to the horizontal that the small parts arriving in the conveying trough slide along the conveying trough to a delivery point of their own accord. However, with conveyors of this type there is the problem that, during upward transport by the conveying platform, parts that lie atop one another or have an unfavorable, upright position are transported to the conveying trough and then do not fall into the conveying trough in a manner that ensures trouble-free further conveyance. In particular, small parts such as screws or welding studs, which have a shank and a head with a diameter greater than the shank, tend to become tangled with one another so that they are not reliably singulated and oriented as they are conveyed upward, and can fall atop one another during delivery to the conveying trough, hindering further transport.
Moreover, there is known from FR 2,092,750 a conveyor for small parts wherein a horizontally oriented conveying trough in a funnel-shaped supply reservoir can be moved from a lower position near the bottom, through the supply of small parts, to a higher delivery position, and can then be pivoted into a position inclined to the horizontal for delivery, so that parts picked up by the conveying trough slide onto an inclined rail that continues further. In order to prevent small parts that are lying crosswise from being picked up by the conveying trough, the conveying trough in this conveyor is bordered on one side by a wall and is provided on the other side with a tipping edge whose spacing from the wall is less than half the length of the parts to be conveyed, so that they fall from the conveying trough before the conveying trough has reached the upper delivery position. However, with this prior art design it can happen that individual parts are picked up by the conveying trough in a standing orientation and are conveyed further in this incorrect orientation, thereby causing problems. It is also possible with this prior art device to pick up parts located one atop the other, especially when the parts are provided with a shouldered head.
In another conveying system for conveying and orienting screws, which is known from DE 4,413,017 A1, a supply reservoir is provided with a platform elevator conveying mechanism having a conveying platform that carries the screws upward along with it. The conveying platform has an outward-inclined carrier end face and is moved past a stationary upper end face that is inclined in the same direction downward toward the outside. The carrier end face of the conveying platform is designed to be inclined downward in a predefined transport direction, so that screws carried along by the upward motion of the conveying platform are individually discharged outward over the upper end face one at a time. On the outside, the discharged screws are caught by a funnel-shaped trough at whose open lower end is provided a vibratory conveying trough that orients the screws that arrive one at a time. This prior art conveying system is complicated and the conveying of the screws is harsh and noisy.